[Tropical] Tropical Weather Discussion

[EMWIN Server]

AXNT20 KNHC 171810
TWDAT

Tropical Weather Discussion
NWS National Hurricane Center Miami FL
210 PM EDT Sat Jun 17 2017

Tropical Weather Discussion for North America, Central America
Gulf of Mexico, Caribbean Sea, northern sections of South
America, and Atlantic Ocean to the African coast from the
Equator to 32N. The following information is based on satellite
imagery, weather observations, radar and meteorological analysis.

Based on 1200 UTC surface analysis and satellite imagery through
1745 UTC.

...SPECIAL FEATURES...

A tropical wave is in the central Atlantic associated with a 1012
mb low centered near 06N40W. Its axis extends from 10N39W to the
low to 01N39W, moving W at 20 kt within the last 24 hours. The
wave is in a region of favorable wind shear and is embedded in a
moderate moist environment at the lower levels according to CIRA
LPW imagery. However, Saharan dry air is entering to its
environment, thus limiting the convection to scattered moderate
from 06N to 09N between 35W and 40W, isolated moderate showers
from 04N to 08N between 42W and 45W. Current convection is being
supported by upper level diffluence. This wave has a medium chance
of becoming a tropical cyclone during the next two days. See the
latest NHC Tropical Weather Outlook under AWISP/WMO headers
MIATWOAT/ABNT20 KNHC for more details.

...TROPICAL WAVES...

A tropical wave is in the E Atlc with axis extending from 10N27W
to 01N28W, moving W at 20 kt within the last 24 hours. The wave
is in a region of favorable wind shear, however the wave lacks
deep convection at the time due to Saharan dry air intrusion to
its environment.

A tropical wave is in the central Atlc with axis extending from
17N47W to 08N48W, moving W at 20 kt within the last 24 hours. The
wave lacks convection at the time due to unfavorable wind shear
and intrusion of Saharan dry air and dust to its environment.

A tropical wave is in the W Caribbean with axis extending from
20N75W to 12N77W, moving W at 10 kt within the last 24 hours.
Low level moisture convergence and upper level divergence support
numerous heavy showers and scattered tstms with possible gusty
winds from 14N to 20N between 74W and 81W, including Jamaica and
adjacent waters.

...MONSOON TROUGH/ITCZ...

The Monsoon Trough extends from the coast of west Africa near
13N16W to 07N22W to 05N35W to 05N44W. The ITCZ extends from
05N44W to 06N57W. Three tropical waves are embedded within the
Monsoon trough/ITCZ. See tropical waves section for information
about convection. Otherwise, numerous heavy showers are in the E
Atlc from 06N to 12N between 16W and 23W. Scattered moderate
convection is from 01S to 07N between 22W and 35W.

...DISCUSSION...

GULF OF MEXICO...

A weak ridge continues to dominate the Gulf region being anchored
by a 1013 mb high near 27N87W, which is forecast to dissipate
within the next 24 hours. The ridge provides light to gentle
variable flow E of 90W and gentle to moderate S-SE winds W of 90W.
Water vapor imagery indicates the presence of a broad upper-level
low covering most of the basin along with very dry air, which is
supporting clear skies and fair weather across most of the basin.
However, weather conditions will change Sunday associated with a
broad area of low pressure forecast to form over the northwestern
Caribbean Sea and the Yucatan Peninsula later today or early tomorrow.
Conditions appear to be favorable for gradual development of this
system while it moves slowly northwestward into the southern Gulf
of Mexico early next week. Latest Tropical Weather Outlook gives
this low pressure a high chance of development through 5 days.

CARIBBEAN SEA...

Convection is on the increase across the western Caribbean. Satellite
imagery show clusters of heavy showers and tstms with possible
gusty winds associated with a surface trough from 21N85W to inland
Honduras near 14N86W and a tropical wave moving across Jamaica.
See the tropical waves section above for details. A diffluent
pattern aloft, associated with the above mentioned upper-level low
over the Gulf of Mexico, is helping to induce all this convective
activity. A broad area of low pressure has formed in this area and
continues to organize. There is a high chance of tropical cyclone
development associated with this area of low pressuere over the
southern or central Gulf of Mexico by early next week. This
system will bring increasing winds and building seas across the
central and western Caribbean this weekend due to a tight
pressure gradient between the low pressure area and the Atlantic
ridge. Aside from fresh to strong winds with gusty winds N of 13N
between 73W and 75W, mainly gentle to moderate winds are
elsewhere. Plenty of moisture and very active weather is also
expected with this low, likely affecting the western and central
Caribbean Sea, Central America, and most of Cuba during this
weekend. Locally heavy rain and gusty winds could occur over parts
of Cuba, the Yucatan Peninsula and Central America.

...HISPANIOLA...

Scattered showers are across the island being supported by the
broad area of diffluence in the NW Caribbean and the area of low
pressure mentioned above. Showers are forecast to continue through
early Sunday.

ATLANTIC OCEAN...

Three tropical waves are moving westward between the coast of
Africa and the Lesser Antilles. Please refer to the Tropical Waves
section above for details. Otherwise, broad high pressure covers
the Atlantic from the Azores to the Florida Peninsula, with a 1026
mb high pressure near 31N34W.

For additional information please visit
http://www.hurricanes.gov/marine

$$
Ramos
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